Robert Wechsler says:

State ethics codes in Connecticut and Wisconsin (and probably elsewhere) have recently run into a serious problem with non-severability problems. A non-severability clause provides that if one provision of a code is found to be unconstitutional, then the entire code becomes null and void.

Such a severe penalty for a minor failing in a law is a sign of what the head of Common Cause Wisconsin, in a recent press release calls "sham reform." Knowing that a part of an ethics code is vulnerable to attack, legislators look like they are in favor of ethics reform, knowing that it will not last. It's a win-win for them, and a lose-lose for everyone else.

This is especially a problem when ethics reform is tied to campaign finance or other sorts of election reform, because those areas are more vulnerable to constitutional issues. Regulating lobbyists is also especially vulnerable.

Once a non-severability clause takes effect, it leads to a great deal of distrust of government, when people realize the ethics reforms they applauded were passed by cynical legislators. Any non-severability clause should be seriously criticized when it comes up. But watch out: they seem to be added at the last second.